Vinyl chloride based polymers are used in a variety of fields since they are cheap and have excellent quality balance.
Vinyl chloride based polymers are largely classified into paste resins and straight resins.
Paste resins are prepared through emulsion polymerization. In particular, monomers, water, a surfactant, and the like are homogenized using a homogenization device, and then moved to a polymerization device for polymerization. The polymerized paste resins are used in wallpaper, linoleum, and the like.
Straight resins are prepared through suspension polymerization. The straight resins are classified into soft and hard products according to use thereof. General soft products are used in wire clothing, wrap films, sheets, and the like using large amounts of plasticizer. The hard products are used in a variety of fields such as pipes, films, window frames, and the like by adding a variety of additives such as impact modifiers, thermal stabilizers, processing aids, pigments, inorganic filler, and the like.
Vinyl chloride based polymers exhibit weak thermal resistance, impact resistance, and mechanical strength. To supplement the problems, thermal stabilizers, impact modifiers, and inorganic materials are added thereto. As the inorganic materials, a variety of materials such as calcium carbonate, silica, titanium oxide, clay, carbon black, zinc oxide, and the like are used depending on required properties. Recently, technology to prepare and use nanoscale composites is being developed.
The nanoscale composites (hereinafter, nanocomposites) are composed of two or more structure or material types, and mean materials having nanoscale phase sizes (10−9 m). In particular, a polymer nanocomposite has mechanical strength such as thermal resistance, impact resistance, and the like dramatically improved by exfoliating and dispersing inorganic nanomaterials of 1 nm to 500 nm over a polymer material. In addition, the polymer nanocomposite may have flexibility and machinability, which are properties of the polymer, and mechanical strength, thermal resistance, and the like, which are properties of inorganic nanomaterials, at the same time, and as such, receives great attention.
The nanocomposites may satisfy required properties when inorganic nanomaterials are uniformly dispersed in polymer materials. However, in the case of the vinyl chloride based polymers, it is extremely difficult to prepare nanocomposites by uniformly dispersing inorganic nanomaterials. Accordingly, in most cases, a method of preparing the vinyl chloride based inorganic composites is limited to a method of mechanically mixing general inorganic materials.